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  • Chemistry  (4)
  • Urinalysis  (4)
  • Amino acids  (3)
  • Bombyx mori  (2)
  • 1
    ISSN: 0022-1910
    Schlagwort(e): Anti-diapause hormone serum ; Bombyx mori ; Diapause hormone ; Embryonic diapause ; Glycogen ; Ovaries ; Suboesophageal ganglion ; Trehalase
    Quelle: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Thema: Biologie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 0022-1910
    Schlagwort(e): Bombyx mori ; Diapause hormone ; Embryonic diapause ; Subesophageal ganglion ; Trehalase
    Quelle: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Thema: Biologie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Amino acids 1 (1991), S. 239-246 
    ISSN: 1438-2199
    Schlagwort(e): Amino acids ; d-Amino-acid oxidase ; d-Aminoaciduria ; Physiological role ; Mutant mice ; d-Amino acids ; Urine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Urine of mutant ddY/DAO− mice lackingd-amino-acid oxidase activity contained more serine and proline than that of normal ddY/DAO+ mice.d-Amino-acid oxidase treatment of urinary amino acids decreased the serine and proline, suggesting that they containedd-isomers. An HPLC analysis confirmed the presence ofd-serine. Urinary serine and proline contents were not decreased when the ddY/DAO− mice were fed a diet which did not contain supplementaryd-methionine or when they were given water containing antibiotics. These results suggest that thed-serine andd-proline do not derive from thed-methionine supplemented in the diet or from intestinal bacteria. In urine of the ddY/DAO− mice, a substance which seemed to bed-methionine sulfoxide and/ord-methionine sulfone was present. It is probably a metabolite of thed-methionine supplemented in the diet. Thed-aminoaciduria in the mutant mice lackingd-amino-acid oxidase activity indicates that this enzyme is involved in the metabolism of thed-amino acids in normal mice.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    International archives of occupational and environmental health 68 (1996), S. 289-297 
    ISSN: 1432-1246
    Schlagwort(e): Key words o-Cresol ; Exposure marker ; Hippuric acid ; Toluene ; Urinalysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Head-space gas chromatography (GC) and high-performance liquid chromatography (HPLC) (with fluorescence detectors) methods were developed for toluene (TOL-U) and o-cresol (CR-U) in urine, respectively. In order to identify the most sensitive urinary indicator of occupational exposure to toluene vapor (TOL-A) among TOL-U, CR-U, and hippuric acid in urine (HA-U), the two methods together with an HPLC (with untraviolet detectors) method for determination of HA-U were applied in the analysis of end-of-shift urine samples from 115 solvent-exposed workers (exposed to toluene at 4 ppm as geometric mean). Regression analysis showed that TOL-U correlated with TOL-A with a significantly higher correlation coefficient than did HA-U or CR-U. With regard to the TOL-A concentrations at which the exposed subjects could be separated from the nonexposed by the analyte, TOL-U achieved separation at 〈10 ppm TOL-A, whereas both HA-U and CR-U did so only when TOL-A was 30 ppm or even higher. The ratio of the analyte concentrations at 50 ppm TOL-A to those at 0 ppm TOL-A was also highest for TOL-U. Overall, the results suggest that TOL-U is a better marker of exposure to toluene vapor than HA-U or CR-U.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    International archives of occupational and environmental health 73 (2000), S. 449-456 
    ISSN: 1432-1246
    Schlagwort(e): Key words Acetone ; Biological monitoring ; Hexane ; 2 ; 5-Hexanedione ; Toluene ; Ethyl acetate ; Urinalysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Objective: To investigate whether metabolic interactions exist between hexane (HEX) and other solvents when co-exposed at the levels below occupational exposure limits. Methods: Workers, 219 men in ten workshops in total, volunteered to participate in the study. They were occupationally exposed to mixtures of HEX and one or more of toluene (TOL), ethyl acetate (EA) and acetone (ACE). Time-weighted average intensity of vapor exposures was monitored by diffusive personal sampling. `Free'- and `total'-2,5-hexanedione (HD) levels in the end-of-shift urine samples were determined by gas chromatography (GC) before and after acid hydrolysis of urine, respectively, and expressed as observed (HDob) or after correction for creatinine concentration (HDcr) or urine specific gravity (HDsg). Possible interaction was examined by multiple regression analysis (MRA), taking either free- or total-HD as a dependent variable, and the four solvent concentrations as independent variables. Results: In most cases, exposure intensity did not exceed the current occupational exposure limits even when additiveness was assumed. In addition that HEX was the most influential independent variable in all cases as expected, the MRA showed that, in cases of free-HD, ACE was also influential to HDob although weakly, but not to HDcr or HDsg. With regard to total-HD, ACE was weakly influential to HDob and HDsg, and EA also weakly to HDcr. The effect of ACE on free- or total-HD was not detected, however, when 22 men exposed only to HEX and ACE were subjected to the same analysis. Similarly, the effect of EA on total-HD was not observed among the remaining 197 men exposed to HEX, TOL and EA only. Conclusions: When the exposures were below occupational exposure limits, the free-HD levels in urine after HEX exposure will not be modified by co-exposures to TOL, EA or ACE.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    International archives of occupational and environmental health 41 (1978), S. 125-138 
    ISSN: 1432-1246
    Schlagwort(e): Amylphenol ; Biological monitoring ; Butylcatechol ; Butylphenol ; Isopropylcatechol ; Methylcatechol ; Nonylphenol ; Octylphenol ; Phenylphenol ; Urinalysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary GLC systems are developed for quantitative urinalysis of leucodermogenic phenols and catechols, i. e., p-tert.-butylphenol, p-tert. Amyphenol, p-octylphenol, p- and o-phenylphenol, 3- and 4-methylcatechol, 3-isopropylcatechol, and 4-tert.-butylcatechol. The systems were successfully applied for the exposure assessment of the workers in factories producing p-tert.-butylphenol, p-octylphenol and/or 4-tert.-butylcatechol. In accordance with estimated exposure intensities, the concentrations in the urine of product packers were higher than those of plant operators and engineers. The levels were reduced by the improvement of hygienic conditions in the workshops. Importance of biological monitoring is discussed in relation with the possible skin penetration. From the data obtained, BP concentration in urine, 2 μg/ml, is tentatively proposed as a urinary biological threshold limit value to prevent leucodermogenic effect.
    Materialart: Digitale Medien
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  • 7
    ISSN: 1432-1246
    Schlagwort(e): Key words Biological monitoring ; Blood analysis ; Diffusive sampling ; Head-space GC ; Tetrachloroethene ; Urinalysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Objective: The present study was initiated to examine a quantitative relationship between tetrachloroethene (TETRA) in blood and urine with TETRA in air, and to compare TETRA in blood or urine with trichloroacetic acid (TCA) in urine as exposure markers. Methods: In total, 44 workers (exposed to TETRA during automated, continuous cloth-degreasing operations), and ten non-exposed subjects volunteered to participate in the study. The exposure to vapor was monitored by diffusive sampling. The amounts of TETRA and TCA in end-of-shift blood and urine samples were measured by either head-space gas chromatography (HS-GC) or automated methylation followed by HS-GC. The correlation was examined by regression analysis. Results: The maximum time-weighted average (TWA) concentration for TETRA-exposure was 46 ppm. Regression analysis for correlation of TETRA in blood, TETRA in urine and TCA in urine, with TETRA in air, showed that the coefficient was largest for the correlation between TETRA in air and TETRA in blood. The TETRA in blood, in urine and in air correlated mutually, whereas TCA in urine correlated more closely with TETRA in blood than with TETRA in urine. The TCA values determined by colorimetry and by the GC method were very similar. The biological marker levels at a hypothetical exposure of 25 ppm TETRA were substantially higher in the present study than were the levels reported in the literature. Possible reasons are discussed. Conclusions: Blood TETRA is the best marker of occupational exposure to TETRA, being superior to the traditional marker, urinary TCA.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Amino acids 13 (1997), S. 379-391 
    ISSN: 1438-2199
    Schlagwort(e): Amino acids ; HPLC ; Mammalian cells ; Bacterial cells
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary High performance liquid chromatography was used to analyze the amino acid composition of cells. A total of 17 amino acids was analyzed. This method was used to compare the amino acid compositions of the following combinations: primary culture and established cells, normal and transformed cells, mammalian and bacterial cells, andEscherichia coli andStaphylococcus aureus. The amino acid compositions of mammalian cells were similar, but the amino acid compositions ofEscherichia coli andStaphylococcus aureus differed not only from mammalian cells, but also from each other. It was concluded that amino acid composition is almost independent of cell establishment and cell transformation, and that the amino acid compositions of mammalian and bacterial cells differ. Thus, it is likely that changes in amino acid composition due to cell transformation or species differences between mammalian cells are negligible compared with the differences between mammalian and bacterial cells, which are more distantly related.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1438-2199
    Schlagwort(e): Amino acids ; Hydroxyproline ; Dabsyl-chloride ; Urine ; High-performance liquid chromatography ; o-Phthalaldehyde
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In order to analyse hydroxyproline (HYP) in urine, a high-performance liquid chromatographic method was modified. The primary amino groups were blocked with o-phthalaldehyde, and then the secondary amino groups were derivatized with 4-dimethylaminoazobenzene-4′-sulphonyl chloride. In addition, the dabsylated samples were treated with ethyl acetate to obtain a simple elution profile in high-performance liquid chromatography. The dabsyl-HYP and -proline were eluted at 4.7 min and 8.0 min, respectively. The chromatographic analysis was completed within 10 min, including the time needed for reequilibration of the column. Using the present method, the concentration of HYP in urine was determined to 260 ± 6µmol/l.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 5 (1971), S. 61-71 
    ISSN: 0030-493X
    Schlagwort(e): Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The mass spectral fragmentation behaviour of N-acyliminopyridinium and isoquinolinium betaines has been investigated. Major fragmentations of the pyridinium betaines can be rationalized in terms of charge localization on the pyridinium nitrogen. The most prominent process is α-cleavage followed by loss of NCO to furnish a pyridine ion. The electron-impact induced fragmentation of N-benzoyliminopyridinium betaine (I) was compared with that of thermolysis. The completely analogous behaviour has been observed in the corresponding isoquinolinium betaines.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
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